/*
 * Copyright (C) 2025 Google LLC
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */
package com.google.cloud.teleport.spanner.spannerio.changestreams.estimator;

import com.google.cloud.Timestamp;
import java.io.Serializable;

/** An estimator to calculate the throughput of the outputted elements from a DoFn. */
public interface ThroughputEstimator<T> extends Serializable {
  /**
   * Updates the estimator with the size of the records.
   *
   * @param timeOfRecords the committed timestamp of the records
   * @param element the element to estimate the byte size of
   */
  void update(Timestamp timeOfRecords, T element);

  /** Returns the estimated throughput for now. */
  default double get() {
    return getFrom(Timestamp.now());
  }

  /**
   * Returns the estimated throughput for a specified time.
   *
   * @param time the specified timestamp to check throughput
   */
  double getFrom(Timestamp time);
}
